Sorry to hear about your problem. So often little dogs act aggressive when really they are worried or insecure. Your baby needs to know that you are the leader, and that he can trust you and your partner to take care of him. I know he usually has shows about bigger dogs, but Ceaser Milan, the dog whisperer, has shows about little guys too. he really has some good advise. You can go to his web site and see tapes of his shows, I bet he will be able to help you.